基本情報

所属

• 理学研究院　生物科学部門　多様性生物学分野

職名

• 准教授

学位

• 博士（理学）（東京都立大学）

ホームページURL

http://kaken.nii.ac.jp/d/r/80374198.ja.html

J-Global ID

• 201301024984333614

研究キーワード

• ショウジョウバエ   食植性昆虫   マイクロサテライト   種分化   分子進化   食性   遺伝学   進化   昆虫   DNA   分子系統   東・東南アジア   マダラテントウ類   アジア地域   DNA解析   分子系統解析   

研究分野

• ライフサイエンス / 多様性生物学、分類学

担当教育組織

•  学士課程　理学部
•  修士課程　理学院
•  博士課程　理学院

職歴

• 2016年10月 - 現在 北海道大学 大学院理学研究院 准教授
• 2009年04月 - 2016年09月 北海道大学 大学院理学研究院 助教

所属学協会

• 日本動物学会   日本昆虫学会   日本遺伝学会   日本進化学会   

研究活動情報

論文

• Single-fly assemblies fill major phylogenomic gaps across the Drosophilidae Tree of Life

  Bernard Y. Kim, Hannah R. Gellert, Samuel H. Church, Anton Suvorov, Sean S. Anderson, Olga Barmina, Sofia G. Beskid, Aaron A. Comeault, K. Nicole Crown, Sarah E. Diamond, Steve Dorus, Takako Fujichika, James A. Hemker, Jan Hrcek, Maaria Kankare, Toru Katoh, Karl N. Magnacca, Ryan A. Martin, Teruyuki Matsunaga, Matthew J. Medeiros, Danny E. Miller, Scott Pitnick, Sara Simoni, Tessa E. Steenwinkel, Michele Schiffer, Zeeshan A. Syed, Aya Takahashi, Kevin H-C. Wei, Tsuya Yokoyama, Michael B. Eisen, Artyom

  bioRxiv 2023年10月02日 [査読無し]
   

  Abstract Long-read sequencing is driving rapid progress in genome assembly across all major groups of life, including species of the family Drosophilidae, a longtime model system for genetics, genomics, and evolution. We previously developed a cost-effective hybrid Oxford Nanopore (ONT) long-read and Illumina short-read sequencing approach and used it to assemble 101 drosophilid genomes from laboratory cultures, greatly increasing the number of genome assemblies for this taxonomic group. The next major challenge is to address the laboratory culture bias in taxon sampling by sequencing genomes of species that cannot easily be reared in the lab. Here, we build upon our previous methods to perform amplification-free ONT sequencing of single wild flies obtained either directly from the field or from ethanol-preserved specimens in museum collections, greatly improving the representation of lesser studied drosophilid taxa in whole-genome data. Using Illumina Novaseq X Plus and ONT P2 sequencers with R10.4.1 chemistry, we set a new benchmark for inexpensive hybrid genome assembly at US $150 per genome while assembling genomes from as little as 35 ng of genomic DNA from a single fly. We present 183 new genome assemblies for 179 species as a resource for drosophilid systematics, phylogenetics, and comparative genomics. Of these genomes, 62 are from pooled lab strains and 121 from single adult flies. Despite the sample limitations of working with small insects, most single-fly diploid assemblies are comparable in contiguity (>1Mb contig N50), completeness (>98% complete dipteran BUSCOs), and accuracy (>QV40 genome-wide with ONT R10.4.1) to assemblies from inbred lines. We present a well-resolved multi-locus phylogeny for 360 drosophilid and 4 outgroup species encompassing all publicly available (as of August 2023) genomes for this group. Finally, we present a Progressive Cactus whole-genome, reference-free alignment built from a subset of 298 suitably high-quality drosophilid genomes. The new assemblies and alignment, along with updated laboratory protocols and computational pipelines, are released as an open resource and as a tool for studying evolution at the scale of an entire insect family.
• Coexistence mechanisms of Colocasiomyia species (Diptera: Drosophilidae) sharing inflorescences of Alocasia odora (Araceae) as a host plant: Comparison between two‐ and three‐species systems

  Masanori J. Toda, Kohei Takenaka Takano, Toru Katoh, Ling Xiao, Jian‐Jun Gao, Masako Yafuso

  Entomological Science 25 2 2022年06月 [査読有り]
  
• Evolution of a neuromuscular sexual dimorphism in the Drosophila montium species group

  Han-qing Liang, Toru Katoh, Kosei Sato, Daisuke Yamamoto, Shuo-yang Wen

  Scientific Reports 11 1 15272  2021年12月 [査読有り]
   

  While epigamic traits likely evolve via sexual selection, the mechanism whereby internal sexual dimorphism arises remains less well understood. Seeking clues as to how the internal sexual dimorphism evolved, we compared the abdominal musculature of 41 Drosophila montium group species, to determine whether any of these species carry a male-specific muscle of Lawrence (MOL). Our quantitative analysis revealed that the size of a sexually dimorphic MOL analog found in 19 montium group species varied widely from species to species, suggesting the gradual evolution of this sexually dimorphic neuromuscular trait. We attempted the ancestral state reconstitution for the presence or absence of the neuromuscular sexual dimorphism in the A5 segment; the neuromuscular sexual dimorphism existed in an old ancestor of the montium group, which was lost in some of the most recent common ancestors of derived lineages, and subsequently some species regained it. This loss-and-gain history was not shared by evolutionary changes in the courtship song pattern, even though both traits were commonly regulated by the master regulator male-determinant protein FruM. It is envisaged that different sets of FruM target genes may serve for shaping the song and MOL characteristics, respectively, and, as a consequence, each phenotypic trait underwent a distinct evolutionary path.
• Phylogeny and evolution of mycophagy in the Zygothrica genus group (Diptera: Drosophilidae)

  Yang Zhang, Takehiro K. Katoh, Cédric Finet, Hiroyuki F. Izumitani, Masanori J. Toda, Hide-aki Watabe, Toru Katoh

  Molecular Phylogenetics and Evolution 163 107257 - 107257 2021年10月 [査読有り][通常論文]
  
• DrosoPhyla: resources for Drosophilid Phylogeny and Systematics

  Cédric Finet, Victoria A Kassner, Antonio B Carvalho, Henry Chung, Jonathan P Day, Stephanie Day, Emily K Delaney, Francine C De Ré, Héloïse D Dufour, Eduardo Dupim, Hiroyuki F Izumitani, Thaísa B Gautério, Jessa Justen, Toru Katoh, Artyom Kopp, Shigeyuki Koshikawa, Ben Longdon, Elgion L Loreto, Maria D S Nunes, Komal K B Raja, Mark Rebeiz, Michael G Ritchie, Gayane Saakyan, Tanya Sneddon, Machiko Teramoto, Venera Tyukmaeva, Thyago Vanderlinde, Emily E Wey, Thomas Werner, Thomas M Williams, Lizandra J Robe, Masanori J Toda, Ferdinand Marlétaz

  Genome Biology and Evolution 13 8 evab179  2021年08月03日 [査読有り]
   

  The vinegar fly Drosophila melanogaster is a pivotal model for invertebrate development, genetics, physiology, neuroscience, and disease. The whole family Drosophilidae, which contains over 4,400 species, offers a plethora of cases for comparative and evolutionary studies. Despite a long history of phylogenetic inference, many relationships remain unresolved among the genera, subgenera and species groups in the Drosophilidae. To clarify these relationships, we first developed a set of new genomic markers and assembled a multilocus dataset of 17 genes from 704 species of Drosophilidae. We then inferred a species tree with highly supported groups for this family. Additionally, we were able to determine the phylogenetic position of some previously unplaced species. These results establish a new framework for investigating the evolution of traits in fruit flies, as well as valuable resources for systematics.
• Taxonomy and evolution of asymmetric male genitalia in the subgenus Ashima Chen (Diptera: Drosophilidae: Phortica Schiner), with descriptions of seven new species

  MASANORI J. TODA, HANS BÄNZIGER, PRADEEP C. SATI, RAJENDRA S. FARTYAL, AWIT SUWITO, TORU KATOH

  Zootaxa 4789 1 1 - 54 2020年06月08日 [査読有り][通常論文]
   

  The taxonomy of the subgenus Ashima of the genus Phortica is revised. A cladistic analysis of 66 morphological characters is conducted, covering 35 species (28 known and 7 new species: Phortica efragmentata sp. nov., P. andreagigoni sp. nov., P. watabei sp. nov., P. halimunensis sp. nov., P. akutsui sp. nov., P. kerinciensis sp. nov., and P. takehiroi sp. nov.) which correspond to 71.4% of 49 total spp. of Ashima. The resulting cladogram shows that the studied species are separated into several clades/subclades/cluster each highly supported with specific synapomorphies. Those clades/subclades/cluster are newly defined as the following species groups, subgroups or complex: the afoliolata, foliiseta, nigrifoliiseta and angulata species groups; the foliiseta, tanabei, nigrifoliiseta and glabra species subgroups; and the foliiseta species complex. The subgenus Ashima is peculiar in having the asymmetric male genitalia as the ground plan and showing the antisymmetry (i.e. intraspecific mirror-image variation) in some species but the directional asymmetry (i.e. side-fixed asymmetry) in others. The evolution of genital asymmetry in this subgenus is estimated by mapping the states (symmetry, directional asymmetry and antisymmetry) of bilateral structures of male genitalia on the cladogram. This ancestral state reconstruction estimates that the directional asymmetry of male genitalia has evolved at the ancestor of this subgenus and then changed to the antisymmetric state independently in two lineages, the angulata + nigrifoliiseta species groups and the foliiseta species complex. In this study, a standardized terminology recently proposed for the male terminalia of Drosophila melanogaster is extendedly adopted to describe the morphology of male terminalia in the subgenus Ashima, one group of the subfamily Steganinae.
• Evolution and diversity of the courtship repertoire in the Drosophila montium species group (Diptera: Drosophilidae).

  Chen AL, Chen CC, Katoh T, Katoh TK, Watada M, Toda MJ, Ritchie MG, Wen SY

  Journal of Evolutionary Biology 32 10 1124 - 1140 2019年10月 [査読有り][通常論文]
  
• Scaptomyza属(双翅目:ショウジョウバエ科)の系統進化

  加藤徹

  昆蟲(ニューシリーズ) 22 2 56 - 65 2019年06月 [査読有り][招待有り]
  
• 同所的に生息する近縁ショウジョウバエ2種の資源利用と遺伝分化

  加藤徹, 三ツ橋圭, 泉谷洋之, 戸田正憲

  昆虫と自然 54 1 30 - 33 2019年01月 [査読無し][招待有り]
  
• A matter of persistence: differential Late Pleistocene survival of two rocky-shore idoteid isopod species in northern Japan

  Shimpei F. Hiruta, Maho Ikoma, Toru Katoh, Hiroshi Kajihara, Matthew H. Dick

  HYDROBIOLOGIA 799 1 151 - 179 2017年09月 [査読有り][通常論文]
   

  The expansion-contraction (EC) model of Pleistocene biogeography and the concept of refugia are of dubious applicability for rocky-shore marine species along the northwest Pacific coast, which was not glaciated at the last glacial maximum (LGM) and likely remained largely habitable by marine communities. We examined the population structure and historical demography of two ecologically similar rocky-intertidal idoteid isopods, Idotea ochotensis and Cleantiella isopus, in northern Japan based on mitochondrial COI and (for I. ochotensis) nuclear ITS nucleotide sequences. We concluded that I. ochotensis persisted in northern Japan across one or more glacial cycles, whereas C. isopus recolonized northern Japan after the LGM. We present an alternative general model for Pleistocene biogeography in temperate to subtropical, non-glaciated coastal regions, wherein species tend to retain large population size and high genetic diversity across glacial cycles in a zone of persistence, with flanking zones of expansion and contraction where the geographical range cyclically expands and contracts (i.e., undergoes latitudinal displacements) with climatic oscillations. We also found that local sea straits had less effect in determining phylogeographic boundaries than a long stretch of unfavorable shore habitat, and that late Holocene sea current patterns appear to have affected fine-scale phylogeographic patterns.
• 北海道大学「恵迪の森」のショウジョウバエ相

  泉谷洋之, 三ッ橋圭, 寺田崇晃, 加藤徹

  昆蟲（ニューシリーズ） 20 3 109 - 119 日本昆虫学会 2017年07月 [査読有り][通常論文]
  
• Multiple origins of Hawaiian drosophilids: Phylogeography of Scaptomyza Hardy (Diptera: Drosophilidae)

  Toru Katoh, Hiroyuki F. Izumitani, Shinji Yamashita, Masayoshi Watada

  ENTOMOLOGICAL SCIENCE 20 1 33 - 44 2017年01月 [査読有り][通常論文]
   

  Scaptomyza is a highly diversified genus in the family Drosophilidae, having undergone an explosive radiation, along with the Hawaiian-endemic genus Idiomyia in the Hawaiian Islands: about 60% of 269 Scaptomyza species so far described are endemic to the Hawaiian Islands. Two hypotheses have been proposed for the origin and diversification of Hawaiian drosophilids. One is the "single Hawaiian origin" hypothesis: Scaptomyza and Idiomyia diverged from a single common ancestor that had once colonized the Hawaiian Islands, and then non-Hawaiian Scaptomyza migrated back to continents. The other is the "multiple origins" hypothesis: Hawaiian Scaptomyza and Idiomyia derived from different ancestors that independently colonized the Hawaiian Islands. A key issue for testing these two hypotheses is to clarify the phylogenetic relationships between Hawaiian and non-Hawaiian species in Scaptomyza. Toward this goal, we sampled additional non-Hawaiian Scaptomyza species, particularly in the Old World, and determined the nucleotide sequences of four mitochondrial and seven nuclear genes for these species. Combining these sequence data with published data for 79 species, we reconstructed the phylogeny and estimated ancestral distributions and divergence times. In the resulting phylogenetic trees, non-Hawaiian Scaptomyza species were interspersed in two Hawaiian clades. From a reconstruction of ancestral biogeography, we inferred that Idiomyia and Scaptomyza diverged outside the Hawaiian Islands and then independently colonized the Hawaiian Islands, twice in Scaptomyza, thus supporting the "multiple origins" hypothesis.
• Phylogeography of the Subgenus Drosophila (Diptera: Drosophilidae): Evolutionary History of Faunal Divergence between the Old and the New Worlds

  Hiroyuki F. Izumitani, Yohei Kusaka, Shigeyuki Koshikawa, Masanori J. Toda, Toru Katoh

  PLOS ONE 11 7 e0160051  2016年07月 [査読有り][通常論文]
   

  The current subgenus Drosophila (the traditional immigrans-tripunctata radiation) includes major elements of temperate drosophilid faunas in the northern hemisphere. Despite previous molecular phylogenetic analyses, the phylogeny of the subgenus Drosophila has not fully been resolved: the resulting trees have more or less varied in topology. One possible factor for such ambiguous results is taxon-sampling that has been biased towards New World species in previous studies. In this study, taxon sampling was balanced between Old and New World species, and phylogenetic relationships among 45 ingroup species selected from ten core species groups of the subgenus Drosophila were analyzed using nucleotide sequences of three nuclear and two mitochondrial genes. Based on the resulting phylogenetic tree, ancestral distributions and divergence times were estimated for each clade to test Throckmorton's hypothesis that there was a primary, early-Oligocene disjunction of tropical faunas and a subsequent mid-Miocene disjunction of temperate faunas between the Old and the New Worlds that occurred in parallel in separate lineages of the Drosophilidae. Our results substantially support Throckmorton's hypothesis of ancestral migrations via the Bering Land Bridge mainly from the Old to the New World, and subsequent vicariant divergence of descendants between the two Worlds occurred in parallel among different lineages of the subgenus Drosophila. However, our results also indicate that these events took place multiple times over a wider time range than Throckmorton proposed, from the late Oligocene to the Pliocene.
• Molecular Phylogeny of Cypridoid Freshwater Ostracods (Crustacea: Ostracoda), Inferred from 18S and28S rDNA Sequences

  Shimpei F. Hiruta, Norio Kobayashi, Toru Katoh, Hiroshi Kajihara

  ZOOLOGICAL SCIENCE 33 2 179 - 185 2016年04月 [査読有り][通常論文]
   

  With the aim of exploring phylogenetic relationships within Cypridoidea, the most species-rich superfamily among the podocopidan ostracods, we sequenced nearly the entire 18S rRNA gene (18S) and part of the 28S rRNA gene (28S) for 22 species in the order Podocopida, with representatives from all the major cypridoid families. We conducted phylogenetic analyses using the methods of maximum likelihood, minimum evolution, and Bayesian analysis. Our analyses showed monophyly for Cyprididae, one of the four families currently recognized in Cypridoidea. Candonidae turned out to be paraphyletic, and included three clades corresponding to the subfamilies Candoninae, Paracypridinae, and Cyclocypridinae. We propose restricting the name Candonidae s. str. to comprise what is now Candoninae, and raising Paracypridinae and Cyclocyprininae to family rank within the superfamily Cypridoidea.
• Introgression and Habitat Segregation in a Pair of Ladybird Beetle Species in the Genus Propylea (Coccinellidae, Coccinellinae) in Northern Japan

  Hiromu Suga, Wataru Hirano, Toru Katoh, Kei W. Matsubayashi, Haruo Katakura

  ZOOLOGICAL SCIENCE 33 6 603 - 610 2016年 [査読有り][通常論文]
   

  The ladybird beetles Propylea quatuordecimpunctata and P. japonica have largely overlapping distributions in northern Japan, and in the laboratory produce fertile hybrids. In this study, we surveyed the distribution and morphological differentiation of these species and the hybrids in natural populations, with a focus on western Hokkaido, northern Japan. Phenotypic analyses were conducted for 987 individuals collected at 90 localities. In addition, the nuclear internal transcribed spacer-II (ITS2) region (549 bp) and part of the mitochondrial cytochrome c oxidase subunit I (COI) gene (700 bp) were sequenced for 620 individuals from 53 localities. Analyses of both phenotypic and genotypic features discriminated two distinct entities assignable to P. quatuordecimpunctataand P. japonica. However, individuals with intermediate phenotypes and/or genotypes also occurred extensively, indicating natural hybridization. Putative P. quatuordecimpunctata individuals were collected across a wide range of altitudes (30-600 m), whereas those of P. japonica were found mostly lower than 300 m alt. In addition, P. quatuordecimpunctata was dominant in semi-open habitats shaded by canopy foliage, whereas P. japonica was frequent in more open habitats. The perceived altitudinal difference in the distributions may thus in part be a consequence of this different habitat preference, as open habitats are more common at lower altitudes in the study area.
• Phylogeny of Epilachna, Henosepilachna, and Some Minor Genera of Phytophagous Ladybird Beetles (Coleoptera: Coccinellidae: Coccinellinae: Epilachnini), with an Analysis of Ancestral Biogeography and Host-Plant Utilization

  Toru Katoh, Shinsaku Koji, Takahide A. Ishida, Kei W. Matsubayashi, Sih Kahono, Norio Kobayashi, Kota Furukawa, Bui Tuan Viet, Joao Vasconcellos-Neto, Charles N. Lange, Georg Goergen, Susumu Nakano, Nan-Nan Li, Guo-Yue Yu, Haruo Katakura

  ZOOLOGICAL SCIENCE 31 12 820 - 830 2014年12月 [査読有り][通常論文]
   

  Ladybird beetles in the tribe Epilachnini include notorious crop pests and model species studied intensively in various fields of evolutionary biology. From a combined dataset of mitochondrial (ND2) and nuclear (28S) DNA sequences, we reconstructed the phylogeny of 46 species of Epilachnini from Asia, Africa, America, and the Australian region: 16 species in Epilachna, 24 species in Henosepilachna, and one species each in Adira, Afidenta, Afidentula, Afissula, Chnootriba, and Epiverta. In our phylogenetic trees, both Epilachna and Henosepilachna were reciprocally polyphyletic. Asian Epilachna species were monophyletic, except for the inclusion of Afissula sp. Asian and Australian Henosepilachna species likewise formed a monophyletic group, excluding H. boisduvali. African Epilachna and Henosepilachna species did not group with their respective Asian and American congeners, but were paraphyletic to other clades (Epilachna species) or formed a separate monophyletic group (Henosepilachna species) together with Chnootriba similis. The American Epilachna species were monophyletic and formed a clade with American Adira clarkii and Asian Afidentula manderstjernae bielawskii; this clade was the sister group to Asian and Australian Henosepilachna, but was distant from Asian Epilachna. Chnootriba was embedded in the African Henosepilachna clade, and Afissula in the Asian Epilachna clade. Epiverta, which is morphologically unique, was the sister group to Asian Epilachna, although with weak support. From reconstructions of biogeographical distribution and host-plant utilization at ancestral nodes, we inferred an African origin for the common ancestor of the species studied, and found the frequency of host shifts to differ greatly between the two major lineages of Epilachnini examined.
• Divergence of East Asians and Europeans Estimated Using Male- and Female-Specific Genetic Markers

  Yoshio Tateno, Tomoyoshi Komiyama, Toru Katoh, Batmunkh Munkhbat, Akira Oka, Yuko Haida, Hiroyuki Kobayashi, Gen Tamiya, Hidetoshi Inoko

  GENOME BIOLOGY AND EVOLUTION 6 3 466 - 473 2014年 [査読有り][通常論文]
   

  To study the male and female lineages of East Asian and European humans, we have sequenced 25 short tandem repeat markers on 453 Y-chromosomes and collected sequences of 72 complete mitochondrial genomes to construct independent phylogenetic trees for male and female lineages. The results indicate that East Asian individuals fall into two clades, one that includes East Asian individuals only and a second that contains East Asian and European individuals. Surprisingly, the European individuals did not form an independent clade, but branched within in the East Asians. We then estimated the divergence time of the root of the European clade as similar to 41,000 years ago. These data indicate that, contrary to traditional views, Europeans diverged from East Asians around that time. We also address the origin of the Ainu lineage in northern Japan.
• Description and molecular phylogeny of a new species of Phoronis (Phoronida) from Japan, with a redescription of topotypes of P. ijimai Oka, 1897

  Masato Hirose, Ryuma Fukiage, Toru Katoh, Hiroshi Kajihara

  ZOOKEYS 398 398 1 - 31 2014年 [査読有り][通常論文]
   

  We describe Phoronis emigi sp. n. as the eighth member of the genus based on specimens collected from a sandy bottom at 33.2 m depth in Tomioka Bay, Amakusa, Japan. The new species is morphologically similar to P. psammophila Cori, 1889, but can be distinguished from the latter by the number of longitudinal muscle bundles in the body wall (56-72 vs. 25-50 in P. psammophila) and the position of the nephridiopores (situated level with the anus vs. lower than the anus in P. psammophila). Using sequences of the nuclear 18S and 28S rRNA genes and the mitochondrial cytochrome c oxidase subunit I (COI) gene, we inferred the relationship of P. emigi to other phoronids by the maximum likelihood method and Bayesian analysis. The analyses showed that P. emigi is closely related to P. hippocrepia Wright, 1856 and P. psammophila Cori, 1889. We describe the morphology of the topotypes and additional material for P. ijimai Oka, 1897. Neither our morphological observations of P. ijimai, nor the phylogenetic analyses based on 18S and COI sequences, contradicts that P. vancouverensis Pixell, 1912 is conspecific with P. ijimai, a synonymy that has long been disputed.
• Colocasiomyia (Diptera: Drosophilidae) revised phylogenetically, with a new species group having peculiar lifecycles on monsteroid (Araceae) host plants

  Rajendra S. Fartyal, Jian-Jun Gao, Masanori J. Toda, Yao-Guang Hu, Kohei Takenaka Takano, Awit Suwito, Toru Katoh, Tomohiro Takigahira, Jian-Tao Yin

  SYSTEMATIC ENTOMOLOGY 38 4 763 - 782 2013年10月 [査読有り][通常論文]
   

  The phylogeny of Colocasiomyia (Drosophilidae) is analysed using data for 70 morphological characters, many of which are re-evaluated from or added to those used previously, for an expanded taxon sample of 24 Colocasiomyia ingroup species. A special focus is put on three species, of which two have remained unresolved for their relationships to other Colocasiomyia species, and the other is a newly discovered species. The analysis results in a single, most parsimonious cladogram, in which a clade comprising the three focal species is recognized along with other clades recovered for the known species groups of Colocasiomyia. Based on this, a new species groupthe gigantea groupis established, including Colocasiomyia gigantea (Okada), C. rhaphidophoraeGao & Toda, n.sp. and C. scindapsaeFartyal & Toda, n.sp. These species of the gigantea group breed on inflorescences/infructescences of the subfamily Monsteroideae (Araceae) exceptionally among Colocasiomyia species, most of which use plants of the subfamily Aroideae as their hosts. Colocasiomyia gigantea uses Epipremnum pinnatum (L.) Engler, C. rhaphidophorae uses Rhaphidophora hookeriSchott and C. scindapsae uses Scindapsus coriaceusEngler as their hosts. The host plants of the gigantea group are epiphytes and differ in the structure of spadix and the fruiting process from those of the Aroideae. To understand how the species of the gigantea group adapt to properties of their host plants, their reproductive ecologymost intensively that of C. giganteais investigated. The lifecycle of C. gigantea is characterized by its relatively slow embryonic development (taking approximately 6 days), the very long duration of the full-grown first instar within the egg capsule (approximately three months) until dehiscence of host infructescence, and its relatively fast larval and pupal development (taking approximately 11 or 12 days). Some morphological adaptations and the reproductive strategy in terms of egg size vs. number' trade-off are discussed in relation to their reproductive habits and peculiar lifecycles.
• Three species of Amphicorina (Annelida, Sabellida, Sabellidae) from Japan, with descriptions of two new species

  Taiki Yoshihara, Shimpei F. Hiruta, Toru Katoh, Hiroshi Kajihara

  ZOOKEYS 187 187 45 - 62 2012年 [査読有り][通常論文]
   

  We describe two new species and redescribe one in the polychaete genus Amphicorina Claparede, 1864 (Sabellidae) from Hokkaido, Japan. Amphicorina ascidicola sp. n. differs from its 38 congeners chiefly in the reduction of the collar, but also in having three pairs of radioles, one pair of ventral radiolar appendages, a bifurcate ventral lobe on the anterior peristomial ring, six abdominal chaetigers, and a large anterior tooth on the abdominal uncini. Amphicorina ezoensis sp. n. has a crenulated collar, three pairs of radioles, and more than eight (12) abdominal chaetigers; A. ezoensis sp. n. shares these character states with A. anneae (Rouse, 1994), A. eimeri (Langerhans, 1880), and A. persinosa (Ben-Eliahu, 1975), but differs from them in having two pairs of ventral radiolar appendages and a non-oblique collar. Amphicorina mobilis (Rouse, 1990) was previously known only from the type locality (New South Wales, Australia), but we identify our Japanese material as conspecific on the basis of morphological and molecular similarity.
• Molecular Systematics of Tanaidacea (Crustacea: Peracarida) Based on 18S Sequence Data, with an Amendment of Suborder/Superfamily-level Classification

  Keiichi Kakui, Toru Katoh, Shimpei F. Hiruta, Norio Kobayashi, Hiroshi Kajihara

  ZOOLOGICAL SCIENCE 28 10 749 - 757 2011年10月 [査読有り][通常論文]
   

  Phylogenetic relationships within Tanaidacea were analyzed based on sequence data for the 18S rRNA gene. Our results strongly supported a monophyletic group composed of Neotanaidae, Tanaoidea, and Paratanaoidea, with the first two taxa forming a clade. These results contradict three previously suggested hypotheses of relationships. Based on the molecular results, and considering morphological similarities/differences between Neotanaidomorpha and Tanaidomorpha, we demoted Suborder Neotanaidomorpha to Superfamily Neotanaoidea within Tanaidomorpha; with this change, the classification of extant tanaidaceans becomes a two-suborder, four-superfamily system. This revision required revision of the diagnoses for Tanaidomorpha and its three superfamilies. The results for Apseudomorpha were ambiguous: this taxon was monophyletic in the maximum likelihood and Bayesian analyses, but paraphyletic in the maximum parsimony and minimum evolution analyses.
• Phylogenetic relationships between Sophophora and Lordiphosa, with proposition of a hypothesis on the vicariant divergences of tropical lineages between the Old and New Worlds in the family Drosophilidae

  Jian-jun Gao, Yao-guang Hu, Masanori J. Toda, Toru Katoh, Koichiro Tamura

  MOLECULAR PHYLOGENETICS AND EVOLUTION 60 1 98 - 107 2011年07月 [査読有り][通常論文]
   

  Despite many studies on the phylogeny of the subgenus Sophophora, its monophyly has not been established, especially in relation to its putative relative, the genus Lordiphosa. We analyzed their phylogenetic relationships using DNA sequence data of two mitochondrial genes (ND2 and CO11)and two nuclear genes (Adh and 28SrRNA). In constructing phylogenetic trees, we accounted for the problem of among-taxa nucleotide compositional heterogeneity, and took a sequence-partitioning approach to allow multiple substitution models for nucleotide sequences that have evolved under different evolutionary processes, particularly developing a novel, sequence-partitioning procedure for Neighbor Joining (NJ) tree construction. Trees constructed by different methods showed an almost identical and strongly supported topology in which Sophophora was paraphyletic: Lordiphosa was placed as the sister to the Neotropical Sophophora consisting of the saltans and willistoni groups, and Sophophora was divided into the clade of Lordiphosa + Neotropical Sophophora and the clade of the obscura + melanogaster groups. Based on the estimated time, 45.9 Mya, of divergence between the Old World Lordiphosa and the Neotropical Sophophora and evidence from paleontology, paleo-geography and -climatology, we propose a hypothesis that this vicariant divergence should have occurred when the North Atlantic Land Bridge between Europe and North America broke in the middle Eocene Epoch. (C) 2011 Elsevier Inc. All rights reserved.
• Systematics and phylogeny of the hoplonemertean genus Diplomma (Nemertea) based on molecular and morphological evidence

  Hiroshi Kajihara, Minerva Olympia, Norio Kobayashi, Toru Katoh, Hai-Xia Chen, Malin Strand, Per Sundberg

  ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY 161 4 695 - 722 2011年04月 [査読有り][通常論文]
   

  We provide a redescription of the poorly known distromatonemertean, Diplomma serpentina ( Stimpson, 1855), a species that has not been reported since its original description. One of the freshly obtained topotypes is designated as a neotype. Based on examination of the new material, as well as the type specimens of three known species, we present a taxonomic revision of the so-far monotypic genus Diplomma Stimpson, 1857, which has been regarded as a dubious taxon since 1904. The following three nominal species are transferred to Diplomma: Paramphiporus albimarginatus Kirsteuer, 1965, Poseidonemertes bothwellae Gibson, 1982, and Correanemertes polyophthalma Gibson & Sundberg, 2001. The genus Paramphiporus Kirsteuer, 1965 is regarded as a junior synonym of Diplomma. Comparison of cytochrome c oxidase subunit I gene ( COI) sequences indicates that D. serpentina is distributed in Indonesia, the Philippines, and Japan. Phylogenetic analyses based on partial sequences of nuclear 28S rRNA and 18S rRNA genes, as well as COI, from a selected number of distromatonemerteans fail to specify the sister relation to Diplomma, although it is suggested that the genus is more closely related to Antarctonemertes, Gononemertes, Nemertellina, Tetraneuronemertes, Oerstedia, and Vulcanonemertes, than to Amphiporus, Cyanophthalma, Geonemertes, Malacobdella, Paranemertes, Poseidonemertes, Prostoma, Tetrastemma, and Zygonemertes. (C) 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161, 695-722.
• First record of the poorly known pelagic nemertean Protopelagonemertes beebei (Nemertea: Hoplonemertea: Polystilifera: Pelagica) from Japanese waters, with discussion of the species identity

  Hiroshi Kajihara, Toru Katoh, Dhugal J. Lindsay

  Marine Biodiversity Records 4 e13 1 - 8 2011年04月 [査読有り][通常論文]
   

  Two specimens of the pelagic nemertean Protopelagonemertes beebei Coe, 1936 were collected in Sagami Bay, Japan. Kimura-2-parameter distance based on the partial sequences (616 base pairs) of cytochrome c oxidase gene between the present material and that previously reported as an unidentified specimen of the genus Protopelagonemertes collected from off California, USA was 5.6%, implying that these are closely related, and may belong to the same species. A description of the internal morphology based on serial transverse sections of the body is provided. The material showed an intermediate character state in the number of proboscis nerves between what had formerly been reported as P. beebei and P. hubrechti (Brinkmann, 1917), posing a question on the species delimitation. © 2011 Marine Biological Association of the United Kingdom.
• ショウジョウバエ分子系統学研究の最前線 (生物進化研究のモデル生物群としてのショウジョウバエ)

  加藤 徹

  低温科学 69 0 1 - 9 北海道大学低温科学研究所 = Institute of Low Temperature Science, Hokkaido University 2011年 [査読有り][通常論文]
   

  ショウジョウバエ科の系統関係については古くから注目され, これまでにいくつかの古典的な研究が知られている. 中でも, Throckmortonは1975年に内部形態や地理的分布などに基づいたショウジョウバエ科の系統に関する仮説を提唱し, 多くの研究者に広く受け入れられてきた. しかし, その後, Grimaldi（1990）は数多くの外部形態を用いて分岐学的解析を行い, Throckmortonの説と大きく異なる仮説を提唱した. それ以来, ショウジョウバエ科の系統関係を分子系統学的見地から再検討しようとする試みが, これまで数多くなされている. 興味深いことに, 分子系統解析に基づく最近の研究結果は, 後から提唱されたGrimaldiの仮説よりも, むしろ古典的なThrockmortonの仮説に近い傾向にある. しかしながら, ハワイ産ショウジョウバエを含むいくつかの重要な分類群の系統関係については, 分子系統解析から, 両者何れの仮説とも異なる独自の見解が新たに得られている. 本稿では, ショウジョウバエにおける最近の分子系統学研究の結果を概説するとともに, ショウジョウバエ系統学の今後の展望について議論する.The phylogeny of Drosophilidae has been of great interest, and several classical studies have been made. Among them, one of the most famous studies was Throckmorton (1975), in which he proposed a phylogenetic framework for Drosophilidae based on the comparisons of internal morphology and biogeography. On the other hand, based on a cladistic analysis of external morphology, Grimaldi (1990) put forward another hypothesis that was substantially different from that of Throckmorton (1975). Since then, many molecular approaches have been undertaken in order to solve this problem. It is noteworthy that many phylogenetic studies using molecular data on the whole are in agreement with Throckmorton's classical hypothesis rather than Grimaldi's. Furthermore, these studies also give some additional findings that are different from either Throckmorton's or Grimaldi's. I review these results and then discus prospects of phylogenetic studies on Drosophilidae.生物進化研究のモデル生物群としてのショウジョウバエ. 北海道大学低温科学研究所編
• Effects of Straits as Dispersal Barriers for the Flightless Roving Carrion Beetle, Silpha perforata (Coleoptera, Silphidae, Silphinae)

  Noritaka Ito, Toru Katoh, Norio Kobayashi, Haruo Katakura

  ZOOLOGICAL SCIENCE 27 4 313 - 319 2010年04月 [査読有り][通常論文]
   

  Population genetic analyses were conducted for the flightless beetle Silpha perforata in northern Japan to evaluate effects of straits as dispersal barriers. In all, 19 populations on the Hokkaido mainland and one population on each of seven adjacent islands were included in the study. Based on partial sequences (853 bp) of the mitochondrial ND2 gene from 365 individuals, we calculated haplotype diversity (h), nucleotide diversity (pi), Tajima's D, and Fu's F(S) statistics for each population. The genetic distance d(A) and fixation index F(ST) were then estimated between populations, excluding two mainland and two island populations with small sample sizes. The results showed that four island populations (Rebun, Rishiri, Yagishiri, and Teuri) were genetically diverged and isolated from mainland populations, including the closest ones, consistent with the assumption that the straits separating these islands from the mainland have functioned as strong barriers against beetle dispersal. However, some factors other than sea barriers may have resulted in the observed divergence of these island populations, since the straits might be too young to permit such divergence (all are estimated to have been finally established approximately 11,000 to 13,000 years BP). On the other hand, the population on Okushiri Island showed little genetic divergence from the nearest mainland population, suggesting current overseas dispersal across the strait (estimated to have been formed more than 200,000 years BP). The present study thus demonstrated that the effects of straits on dispersal can be diverse, even for species of terrestrial invertebrates with limited dispersal ability.
• Detection of ecological hybrid inviability in a pair of sympatric phytophagous ladybird beetles (Henosepilachna spp.)

  Masakazu Kuwajima, Norio Kobayashi, Toru Katoh, Haruo Katakura

  ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA 134 3 280 - 286 2010年03月 [査読有り][通常論文]
   

  Ecological speciation is a process by which reproductive isolation evolves as the result of divergent natural selection between populations inhabiting distinct environments or exploiting alternative resources. Ecological hybrid inviability provides direct evidence for ecological speciation. To detect ecological hybrid inviability, we examined survival rates to the second instar of F1 hybrids and backcross hybrids in a pair of sympatric phytophagous ladybird beetles, Henosepilachna niponica Lewis and Henosepilachna yasutomii Katakura (Coleoptera: Coccinellidae: Epilachninae), reared on their respective host plants, thistle [Cirsium alpicola Nakai (Asteraceae)] and blue cohosh [Caulophyllum robustum Maxim. (Berberidaceae)], and on a common food plant, Japanese nightshade [Solanum japonense Nakai (Solanaceae)]. Hybrid larvae reared on leaves of the Japanese nightshade always had high rates of survival, irrespective of the crossing type of their parents, suggesting a lack of intrinsic hybrid inviability between the two species. In contrast, survival rates on thistle and blue cohosh varied greatly. On blue cohosh, the survival rate of F1 hybrids was nearly as high as that of H. yasutomii, but on thistle, survival was significantly lower than of H. niponica. Survival rates of backcross hybrids on the two host plants were intermediate between those of the parents, showing a reversed rank order of different types of backcross hybrids on the two food plant species. These results suggest that ecological hybrid inviability exists between H. niponica and H. yasutomii, although the two species do not show intrinsic hybrid inviability. Thus, our study supports the hypothesis that H. niponica and H. yasutomii underwent ecological speciation by divergent selection.
• Molecular phylogenetic analysis of three groups of Asian epilachnine ladybird beetles recognized by the female internal reproductive organs and modes of sperm transfer

  Norio Kobayashi, Yuri Ohta, Toru Katoh, Sih Kahono, Sri Hartini, Haruo Katakura

  JOURNAL OF NATURAL HISTORY 43 27-28 1637 - 1649 2009年 [査読有り][通常論文]
   

  We determined partial sequences of the nuclear 28S ribosomal RNA gene (717 base pairs) and mitochondrial DNA NADH-dehydrogenase subunit 2 gene (535 base pairs) of 25 species of phytophagous ladybird beetles from Asia that comprise 16 species of the genus Henosepilachna and nine species of the genus Epilachna, and reconstructed the phylogenetic trees for each gene by the maximum parsimony and maximum likelihood methods. The estimated phylogenetic relationships were consistent with those obtained by the mode of sperm transfer and female internal reproductive system, and supported an earlier assumption that very similar elytral spot patterns of some sympatric members of epilachnine beetles evolved independently.
• Comment on the proposed conservation of usage of Drosophila Fallén, 1823 (Insecta, Diptera)

  van der Linde K, Bächli G, Toda MJ, Zhang WX, Katoh T, Hu YG, Spicer GS

  Bulletin of Zoological Nomenclature 65 4 304 - 307 2008年12月 [査読有り][通常論文]
  
• 反射出血を利用した昆虫類のDNA解析

  加藤 徹, 古川 恒太, 片倉 晴雄

  昆蟲. ニューシリーズ 11 1 25 - 31 日本昆虫学会 2008年03月 [査読有り][通常論文]
   

  テントウムシなど一部の昆虫が行う反射出血(reflex bleeding)に注目し,対象生物を殺さずにDNAを抽出して解析する手法の確立を試みた.最初に,反射出血によって分泌された血液からDNAを効率よく抽出する方法について検討した.次に,抽出DNAを鋳型としてPCR反応を行い,塩基配列の決定を試みることで,反射出血を用いたDNA解析の可能性を検証した.その結果,シリカゲルを用いた抽出法により,反射出血からDNAを採取することができた.また,少なくとも,ミトコンドリアDNAのND2や核の28Sといったような,系統解析に広く用いられている遺伝子座については,反射出血DNAを用いた遺伝子解析が実際に可能であることを示した.
• Drosophila Fallén, 1832 (Insecta, Diptera): proposed conservation of usage

  van der Linde K, Bächli G, Toda MJ, Zhang WX, Katoh T, Hu YG, Spicer GS

  Bulletin of Zoological Nomenclature 64 4 238 - 242 2007年12月 [査読有り][通常論文]
  
• Phylogeny of the Drosophila immigrans species group (Diptera : Drosophilidae) based on Adh and Gpdh sequences

  Toru Katoh, Daisuke Nakaya, Koichiro Tamura, Tadashi Aotsuka

  ZOOLOGICAL SCIENCE 24 9 913 - 921 2007年09月 [査読有り][通常論文]
   

  The immigrans species group in the Drosophilinae is one of the representative species groups of Drosophila in East Asia. Although this group constitutes a significant part of the drosophilid fauna in the Old World, only a few species have been analyzed in previous molecular phylogenetic studies. To study the phylogeny of the immigrans group, we analyzed the nucleotide sequences of two nuclear genes, alcohol dehydrogenase (Adh) and glycerol-3-phosphate dehydrogenase (Gpdh), for 36 drosophilid species, including 12 species of the immigrans group. In the resultant phylogenetic trees, 10 species of the immigrans group (D. immigrans, D. formosana, D. ruberrima, D. albomicans, D. nasuta, D. neonasuta, D. pailidifrons, D. hypocausta, D. neohypocausta, D. siamana) consistently formed a clade (the immigrans group proper), although the phylogeny within this clade did not exactly correspond to the classification of species subgroups. However, D. annulipes and D. quadrilineata, both of which belong to the quadrilineata subgroup of the immigrans group, were not included in the immigrans group proper. Furthermore, we obtained the unexpected result that D. annulipes was included in a clade comprising Scaptomyza and Hawaiian Drosophila, together with D. maculinotata of the funebris group, although the phylogenetic relationships within this clade remain uncertain and need to be substantiated with further studies. Thus, according to the present study, the immigrans group is polyphyletic.
• Genetic features of Khoton Mongolians revealed by SNP analysis of the X chromosome

  T Katoh, S Mano, B Munkhbat, K Tounai, G Oyungerel, GT Chae, H Han, GJ Jia, K Tokunaga, N Munkhtuvshin, G Tamiya, H Inoko

  GENE 357 2 95 - 102 2005年09月 [査読有り][通常論文]
   

  The Khoton Mongolian population is a small and relatively isolated ethnic group residing predominantly in the northwestern part of Mongolia. A recent genetic study of the Y chromosome revealed that the major Mongolian ethnic groups have a relatively close genetic affinity to populations in the northern part of East Asia, while the Khoton population reflected an apparent genetic differentiation from the other Mongolian populations. To further investigate the genetic features of the Khoton and the other Mongolian populations, we analyzed the single nucleotide polymorphisms (SNPs) in the Xq13.3 region, which is thought to have an extremely low, level of recombination in the human X chromosome. We found that the frequency distribution of Xq13.3 haplotypes in the Khoton population was substantially different from those in three other Mongolian populations (Khalkh, Uriankhai, and Zakhchin). The same relationship was also revealed by the results from the population tree and principal-component (PC) analysis based on the allele frequencies. These results are largely consistent with the hypothesis that the Khoton population descended from a nomadic tribe of Turkish origin, which has been supported by previous anthropological, historical, and Y-chromosome studies. However, the population structure analysis produced an additional finding, namely, that the Khoton population is likely to be an admixed population. (C) 2005 Elsevier B.V. All rights reserved.
• Phylogeny and evolution of butterflies of the genus Parnassius: Inferences from mitochondrial 16S and ND1 sequences

  Toru Katoh, Anton Chichvarkhin, Takashi Yagi, Keiichi Moto

  ZOOLOGICAL SCIENCE 22 3 343 - 351 2005年03月 [査読有り][通常論文]
   

  Phylogenetic relationships among species of the genus Parnassius and its related taxa were analyzed by comparing nucleotide sequences of mitochondrial 16S ribosomal RNA (504 sites) and NADH-dehydrogenase subunit 1 (469 sites). In the phylogenetic trees, Parnassius was found to be most closely related to Hypermnestra helios, whereas Archon apollinus, which has been classified in the tribe Parnassiini together with Parnassius and Hypermnestra, was more closely related to members of the tribe Zerynthiini. Within the Parnassius clade, six major clades corresponding to species groups were well supported, although the phylogenetic relationships among them were not clear. Although the results of the present study were in agreement with those of a previous phylogenetic study based on mitochondrial NADH-dehydrogenase subunit 5 sequences, our study strongly supported a close relationship between Parnassius and Hypermnestra, which was not well supported in the previous study.
• Genetic features of Mongolian ethnic groups revealed by Y-chromosomal analysis

  T Katoh, B Munkhbat, K Tounai, S Mano, H Ando, G Oyungerel, GT Chae, H Han, GJ Jia, K Tokunaga, N Munkhtuvshin, G Tamiya, H Inoko

  GENE 346 63 - 70 2005年02月 [査読有り][通常論文]
   

  About 20 ethnic groups reside in Mongolia. On the basis of genetic and anthropological studies, it is believed that Mongolians have played a pivotal role in the peopling of Central and East Asia. However, the genetic relationships among these ethnic groups have remained obscure, as have their detailed relationships with adjacent populations. We analyzed 16 binary and 17 STR polymorphisms of human Y chromosome in 669 individuals from nine populations, including four indigenous ethnic groups in Mongolia (Khalkh, Uriankhai, Zakhchin, and Khoton). Among these four Mongolian populations, the Khalkh, Uriankhai, and Zakhchin populations showed relatively close genetic affinities to each other and to Siberian populations, while the Khoton population showed a closer relationship to Central Asian populations than to even the other Mongolian populations. These findings suggest that the major Mongolian ethnic groups have a close genetic affinity to populations in northern East Asia, although the genetic link between Mongolia and Central Asia is not negligible. (c) 2004 Elsevier B.V. All rights reserved.
• Notes on the maximum likelihood estimation of haplotype frequencies

  S Mano, N Yasuda, T Katoh, K Tounai, H Inoko, T Imanishi, G Tamiya, T Gojobori

  ANNALS OF HUMAN GENETICS 68 257 - 264 2004年05月 [査読有り][通常論文]
   

  The maximum likelihood estimation (MLE) is one of the most popular ways to estimate haplotype frequencies of a population with genotype data whose linkage phases are unknown. The MLE is commonly implemented in the use of the Expectation-Maximization (EM) algorithm. It is known that the EM algorithm carries the risk that an estimator may converge erroneously to one of the local maxima or saddle points of the likelihood surface, resulting in serious errors in the MLE of haplotype frequencies. In this note, by theoretical treatments we present the necessary and sufficient conditions that the local maxima or saddle points on the likelihood surface appear. As a rule of thumb, that the difference between the coupling and repulsive haplotype frequencies in phase known individuals is 3/2 times larger than the frequency of phase ambiguous individuals is the sufficient condition that the likelihood surface is unimodal. Moreover, we present the analytic solution to the biallelic two-locus problem, and construct a general algorithm to obtain the global maximum.
• Molecular systematics and evolution of the "Apollo" butterflies of the genus Parnassius (Lepidoptera : Papilionidae) based on mitochondrial DNA sequence data

  K Omoto, T Katoh, A Chichvarkhin, T Yagi

  GENE 326 141 - 147 2004年02月 [査読有り][通常論文]
   

  Sequences of 777 bp of mtDNA-ND5 locus were determined in order to shed light on the molecular systematics and evolution of the "Apollo" butterflies. Examined were nearly all of about 50 species of the genus Parnassius, together with seven species of the allied genera in the subfamily Parnassiinae (Papilionidae). The NJ and the MP phylogenetic trees show that the "Apollos" constitute a monophyletic group, comprising a number of cluster groups probably reflecting a relatively rapid radiation in evolution. The clusters of species-groups denoted I-VIII correspond to those species-groups recognized on the basis of morphological characters. Our findings will also help understand the biological relationships among several species or subspecies on which the classical taxonomy is in dispute. The unexpected finding is that among the samples of allied genera compared, Hypermnestra helios appears to be the most closely related to the "Apollos", despite morphological and behavioral dissimilarity. Furthermore, in contrast to the previous higher taxonomy, Archon apollinus which is classified in the tribe Parnassiini was found genetically closer to the tribe Zerynthiini, raising a taxonomic controversy. (C) 2003 Elsevier B.V. All rights reserved.
• Genetic isolates in East Asia: A study of linkage disequilibrium in the X chromosome

  T Katoh, S Mano, T Ikuta, B Munkhbat, K Tounai, H Ando, N Munkhtuvshin, T Imanishi, H Inoko, G Tamiya

  AMERICAN JOURNAL OF HUMAN GENETICS 71 2 395 - 400 2002年08月 [査読有り][通常論文]
   

  The background linkage disequilibrium (LD) in genetic isolates is of great interest in human genetics. Although many empirical studies have evaluated the background LD in European isolates, such as the Finnish and Sardinians, few data from other regions, such as Asia, have been reported. To evaluate the extent of background LD in East Asian genetic isolates, we analyzed the X chromosome in the Japanese population and in four Mongolian populations (Khalkh, Khoton, Uriankhai, and Zakhchin), the demographic histories of which are quite different from one another. Fisher's exact test revealed that the Japanese and Khalkh, which are the expanded populations, had the same or a relatively higher level of LD than did the Finnish, European American, and Sardinian populations. In contrast, the Khoton, Uriankhai, and Zakhchin populations, which have kept their population size constant, had a higher background LD. These results were consistent with previous genetic anthropological studies in European isolates and indicate that the Japanese and Khalkh populations could be utilized in the fine mapping of both complex and monogenic diseases, whereas the Khoton, Uriankhai, and Zakhchin populations could play an important role in the initial mapping of complex disease genes.
• Molecular phylogeny of butterflies Parnassius glacialis and P-stubbendorfii at various localities in East Asia

  T Yagi, T Katoh, A Chichvarkhin, T Shinkawa, K Omoto

  GENES & GENETIC SYSTEMS 76 4 229 - 234 2001年08月 [査読有り][通常論文]
   

  The phylogeny of butterflies, Parnassius stubbendorfii and R glacialis, collected at various localities in the Japan archipelago and the eastern part of the Asian continent was analyzed using mitochondrial DNA sequences coding for NADH dehydrogenase subunit 5 (805 bp). The molecular phylogenetic trees revealed that R glacialis and R stubbendorfii diverged from a common ancestor, and then the populations inhabiting the Japan archipelago and the Asian continent diverged in each species. The reliability of these divergences was supported by high bootstrap values. The divergences within the Japan archipelago and within the Asian continent in each species were unclear because of low bootstrap values. The genetic distance and a rough time-estimation in the UPGMA tree suggest that the both populations of R glacialis and R stubbendorfii may have been isolated in the Japan archipelago at the early time (about 1.7-2.0 Mya) of the glacial period in the Pleistocene. The genetic distance between the Japanese and the continental subspecies may be large enough that they can be classified as different species, in comparison with the genetic distances among some other parnassian species.
• Phylogenetic position of the subgenus Lordiphosa of the genus Drosophila (Diptera : Drosophilidae) inferred from alcohol dehydrogenase (Adh) gene sequences

  T Katoh, K Tamura, T Aotsuka

  JOURNAL OF MOLECULAR EVOLUTION 51 2 122 - 130 2000年08月 [査読有り][通常論文]
   

  We analyzed the phylogenetic relationship between the species of Lordiphosa and other Drosophilidae using alcohol dehydrogenase (Adh) gene sequences. The phylogenetic trees consistently show that the four species Drosophila kurokawai, D. collinella, D. stackelbergi, and D. clarofinis, which include three species groups of Lordiphosa, form a monophyletic clade. This clade is placed as a sister group to the willistoni and saltans groups of Sophophora. On the other hand, three species of Lordiphosa, D. tenuicauda, D. pseudotenuicauda, and D. acutissima, all of which belong to the tenuicauda group, are not shown to be related to the major Lordiphosa lineage. In the phylogenetic toes, these species are included into the clade comprised of Drosophila and Hirtodrosophila, although it remains uncertain whether the tenuicauda group is a monophyletic group or not. These results indicate that Lordiphosa is polyphyletic and that most of the members of the subgenus have a close relationship to the neotropical groups of Sophophora. The above conclusion is compatible with the hypothesis of Okada (Mushi [1963] 37:79-100) and Lastovka and Maca (Acta Ent Bohemoslov [1978] 75:404-420) that Lordiphosa is most closely related to Sophophora; in contrast, our results contradict the hypothesis of Grimaldi (Bull Am Mus Nat Hist [1990] 197:1-139) that Lordiphosa is a sister group to the genus Scaptomyza.

その他活動・業績

• 同所的に生息する2種のヘラムシが見せる異なる集団構造

  蛭田 眞平, 生駒 真帆, 加藤 徹, 柁原 宏, Dick Matthew H うみうし通信 (96) 6 -8 2017年09月 [査読無し][通常論文]
  
• Origin and evolutionary history of the genus Scaptomyza (Diptera: Drosophilidae)

  Toru Katoh, Shinji Yamashita, Watada Masayoshi GENES & GENETIC SYSTEMS 87 (6) 384 -384 2012年12月 [査読無し][通常論文]
  
• Phylogenetic relationships and evolution of host shifts for the phytophagous ladybird beetles of Epilachninae

  Toru Katoh, Norio Kobayashi, Sih Kahono, Harou Katakura GENES & GENETIC SYSTEMS 84 (6) 446 -446 2009年12月 [査読無し][通常論文]
  
• Phylogenetic relationship of Asian and African species of epilachnine ladybird beetles

  Toru Katoh, Norio Kobayashi, Yuri Ohta, Susumu Nakano, Sih Cahono, Takahide Lshida, Helmt Fuersch, Haruo Katakura ZOOLOGICAL SCIENCE 21 (12) 1273 -1273 2004年12月 [査読無し][通常論文]
  
• The Epilachna alternans complex (coleoptera : coccinellidae) in indonesia: Their phylogeny and diversity in morphology and host plants

  Yuri Ohta, Norio Kobayashi, Toru Katoh, Susumu Nakano, Sih Kahono, Haruo Katakura ZOOLOGICAL SCIENCE 21 (12) 1268 -1268 2004年12月 [査読無し][通常論文]
  
• Study of the stratification of Japanese founding lineages.

  K Tounai, S Mano, T Katoh, B Munkhbat, H Ando, G Oyungerel, H Han, N Saitou, K Tokunaga, N Munkhtuvshin, H Inoko, G Tamiya AMERICAN JOURNAL OF HUMAN GENETICS 73 (5) 400 -400 2003年11月 [査読無し][通常論文]
  
• Mongolian populations as genetic resource: Challenges towards genetic study in Mongolians.

  B Munkhbat, K Tounai, T Katoh, S Mano, H Ando, S Ando, N Baasanjav, G Batmunkh, H Inoko, G Tamiya, N Munkhtuvshin AMERICAN JOURNAL OF HUMAN GENETICS 73 (5) 395 -395 2003年11月 [査読無し][通常論文]
  
• SNP variation in a non-coding region of Xq13.3 in East Asia.

  T Katoh, K Tounai, S Mano, H Ando, B Munkhbat, N Munkhtuvshin, K Tokunaga, G Jia, H Inoko, G Tamiya AMERICAN JOURNAL OF HUMAN GENETICS 73 (5) 395 -395 2003年11月 [査読無し][通常論文]
  
• Genetic diversity in Mongolians and Japanese: A comparison of Y-chromosome, mitochondrial DNA and X-chromosome variations.

  B Munkhbat, K Tounai, T Katoh, T Ikuta, H Ando, A Yamamoto, R Sato, G Oyungerel, G Tamiya, N Munkhtuvshin, K Tokunaga, H Inoko AMERICAN JOURNAL OF HUMAN GENETICS 69 (4) 399 -399 2001年10月 [査読無し][通常論文]
  

受賞

• 2018年09月 日本昆虫学会 2018年度 論文賞
   Multiple origins of Hawaiian drosophilids: Phylogeography of Scaptomyza Hardy (Diptera: Drosophilidae). 

  受賞者: 加藤徹;泉谷洋之;山下伸志;和多田正義

共同研究・競争的資金等の研究課題

• 同所的に分布する近縁ショウジョウバエ2種の資源利用と遺伝分化

  文部科学省：科学研究費補助金（基盤研究(C)）

  研究期間 : 2016年04月 -2019年03月 

  代表者 : 加藤徹
• ゲノムから1遺伝子まで網羅的DNA配列情報を使った分子系統解析法の確立

  文部科学省：科学研究費補助金(基盤研究(B))

  研究期間 : 2012年04月 -2016年03月 

  代表者 : 戸田 正憲
• 海産動物の分散障壁に関する研究

  文部科学省：科学研究費補助金（基盤研究(B)）

  研究期間 : 2011年04月 -2016年03月 

  代表者 : Matthew H. Dick
• Scaptomyza属ショウジョウバエの系統進化

  文部科学省：科学研究費補助金(基盤研究(C))

  研究期間 : 2012年04月 -2015年03月 

  代表者 : 加藤 徹
• 東南アジアで進行中のニジュウヤホシテントウの食草変換:その時間的・空間的動態

  文部科学省：科学研究費補助金(基盤研究(B))

  研究期間 : 2011年04月 -2014年03月 

  代表者 : 片倉 晴雄
• 食性に関わる遺伝子群の探索と分子進化:キノコ食ショウジョウバエを中心に

  文部科学省：科学研究費補助金(若手研究(B))

  研究期間 : 2010年04月 -2012年03月 

  代表者 : 加藤 徹

   

  昆虫の多様性が非常に高い理由の一つとして、彼らの食性が著しく多様化したことが挙げられる。本研究課題は、キノコ食という特殊な食性を持つショウジョウバエに注目し、キノコ食のショウジョウバエ系統で特異的に認められた遺伝的変異に対し、自然選択がどのように作用したかを検証することを目的とする。本年度はまず、食性関連因子の分子進化学的解析の基盤となる系統学的情報の収集を目的に、ショウジョウバエの系統学研究で一般的に使われている遺伝子を用いて分子系統樹を構築し、キノコ食およびその他のショウジョウバエ間の系統関係を推定した。その結果、得られた分子系統樹において、キノコ食のショウジョウバエは必ずしも単系統的にまとまらず、ショウジョウバエ科の中で、キノコ食形質が複数回独立して生じた可能性が示唆された。また、キノコ食ショウジョウバエとして有名な分類群のひとつであるDrosophila属のquinaria種群のショウジョウバエは、キノコ食以外のいくつかのショウジョウバエとともに、ある特定の時期に急速に分化した可能性が示唆された。次に、キノコ食のショウジョウバエで特異な遺伝的変異を検出することを目的に、ショウジョウバエ科12種のゲノムのデータベースから、食性の進化に関わると予想される遺伝子を検索し、得られた配列をもとにPCRプライマーをそれぞれ設計した。そして、キノコ食ショウジョウバエ数種のDNAを鋳...
• スーパー系統樹解析によるショウジョウバエ属の系統推定と分類体系の改訂

  文部科学省：科学研究費補助金（基盤研究(C)）

  研究期間 : 2008年04月 -2011年03月 

  代表者 : 胡 耀光

   

  代表的なモデル生物であるキイロショウジョウバエを含むショウジョウバエ属全体の分類体系の改訂を視野に入れて,問題となるいくつかの分類群について,主にDNA分子情報を用いて系統解析を行った.また,将来ゲノムサイズの巨大DNA塩基配列データベース情報を使って系統解析を効率的に行うことをめざして,複数の遺伝子の異なる進化パターンを考慮した分節的解析法を近隣接合法に導入するための新しいプログラムを開発した.
• 食植性昆虫における食草変換の分子基盤の解明

  文部科学省：科学研究費補助金(若手研究(B))

  研究期間 : 2007年04月 -2010年03月 

  代表者 : 加藤 徹

   

  食草の違いだけで生殖的に隔離されていることが予想されているルイヨウマダラテントウおよびヤマトアザミテントウの2種(集団)について、マイクロサテライトマーカーを設定し、集団内多型および種間の遺伝的分化の解析を行なった。その結果、設定した8つのマイクロサテライト遺伝子座のうち、少なくとも3つの遺伝子座で多型が認められたが、何れもアリル多型の程度が非常に小さく、かつ集団間における顕著な遺伝分化は認められなかった。このことは、両集団がごく最近、極めて短時間のうちに分化を遂げたため、食草選択に関わる遺伝子の変異以外、ゲノム間の遺伝分化がほとんど生じてないことを示唆する。
• アジア地域ショウジョウバエ相の多様性形成過程:その包括的理解をめざして

  文部科学省：科学研究費補助金(基盤研究(B))

  研究期間 : 2007年04月 -2010年03月 

  代表者 : 青塚 正志, 戸田 正憲, 渡部 英昭, 木村 正人, 高森 久樹, 屋富祖 昌子, 加藤 徹

   

  ショウジョウバエ類は生命科学における最も優れた研究材料の1つであり,多くの研究分野の研究発展に貢献してきた.現在までに約3、800種が知られているが,いろいろな環境に適応放散しており、生物の適応と進化を探求する上でも優れた分類群である.本研究では、最大の属であるショウジョウバエ属およびその中のシマショウジョウバエ亜属の側系統性を確認するとともに,アジアグリーンベルトに沿ったショウジョウバエ科の多様性形成機構について,多くの重要な知見を得た.
• 食植性昆虫の種分化:食草変換が生殖隔離におよぼす多面的影響の評価

  文部科学省：科学研究費補助金(基盤研究(A))

  研究期間 : 2006年04月 -2010年03月 

  代表者 : 片倉 晴雄, 青塚 正志, 中野 進, 藤山 直之, 加藤 徹

   

  マダラテントウ類、ハムシ類を材料として、食草変換が近縁集団間の生殖隔離に及ぼす影響の評価を行い、食草の違いが生息地選択を通してただちに非常に強い生態的隔離を生み出すこと、温帯域においてはそれに加えて食草の季節消長の違いが産卵/休眠スケジュールに影響を与えることを明らかにした。さらに、食草変換の平行進化、急速な食草変換、食草利用能力の可塑性・潜在能力、食草の個体変異の影響などに関して実例を示した。

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